249: def initialize
250: @drift = 0
251: @last_clock = (Time.now.to_f * CLOCK_MULTIPLIER).to_i
252: @mutex = Mutex.new
253:
254: state_file = self.class.state_file
255: if state_file && File.size?(state_file) then
256: next_sequence
257: else
258: @mac = mac_address
259: fail "Cannot determine MAC address from any available interface, tried with #{mac_address}" if @mac == 0
260: @sequence = rand 0x10000
261:
262:
263: File.open(state_file, 'w') { |f| f.chmod(self.class.mode) } if state_file && !File.exists?(state_file)
264:
265: if state_file
266: open_lock 'wb' do |io|
267: write_state io
268: end
269: end
270: end
271: end